virStorageFileGetLVMKey and virStorageFileGetSCSIKey
both return heap allocated strings, so the return value
should not be marked const.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Commit e0c469e58b that fixes the detection
of image chain wasn't complete. Iteration through the backing image
chain has to stop at the last existing image if some of the images are
missing otherwise the backing chain that is cached contains entries with
paths being set to NULL resulting to:
error: Unable to allow access for disk path (null): Bad address
Fortunately stat() is kind enough not to crash when it's presented with
a NULL argument. At least on Linux.
82507838 refactored the code to keep both the raw and canonicalized form
of the backingStore, which breaks badly when the storage pool contains a
storage volume, which is missing its backing store file:
# ./daemon/libvirtd -l
2012-11-07 12:43:33.279+0000: 22175: info : libvirt version: 1.0.0
2012-11-07 12:43:33.279+0000: 22175: error : absolutePathFromBaseFile:542 : Can't canonicalize path '/var/lib/libvirt/images/base.qcow2': No such file or directory
2012-11-07 12:43:33.280+0000: 22175: error : storageDriverAutostart:115 : Failed to autostart storage pool 'default': Can't canonicalize path '/var/lib/libvirt/images/base.qcow2': No such file or directory
This is because virStorageFileGetMetadataFromBuf() aborts with -1 if the
filename of the backingStore can not be canonicalized:
#0 absolutePathFromBaseFile () at util/storage_file.c:541
#1 virStorageFileGetMetadataFromBuf () at util/storage_file.c:728
#2 virStorageFileGetMetadataFromFD () at util/storage_file.c:932
#3 virStorageBackendProbeTarget () at storage/storage_backend_fs.c:94
#4 virStorageBackendFileSystemRefresh () at storage/storage_backend_fs.c:849
#5 storagePoolStart () at storage/storage_driver.c:700
#6 virStoragePoolCreate () at libvirt.c:12471
...
Treat files which miss their backing file as standalone files.
Signed-off-by: Philipp Hahn <hahn@univention.de>
The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
There are multiple reasons canonicalize_file_name() used in
absolutePathFromBaseFile helper can fail. This patch enhances error
reporting from that helper.
Yet another instance of where using plain open() mishandles files
that live on root-squash NFS, and where improving the API can
improve the chance of a successful probe.
* src/util/storage_file.h (virStorageFileProbeFormat): Alter
signature.
* src/util/storage_file.c (virStorageFileProbeFormat): Use better
method for opening file.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo): Update caller.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget):
Likewise.
In order to temporarily label files read/write during a commit
operation, we need to crawl the backing chain and find the absolute
file name that needs labeling in the first place, as well as the
name of the file that owns the backing file.
* src/util/storage_file.c (virStorageFileChainLookup): New
function.
* src/util/storage_file.h: Declare it.
* src/libvirt_private.syms (storage_file.h): Export it.
In order to search for a backing file name as literally present
in a chain, we need to remember if the chain had relative names.
Also, searching for absolute names is easier if we only have
to canonicalize once, rather than on every iteration.
* src/util/storage_file.h (_virStorageFileMetadata): Add field.
* src/util/storage_file.c (virStorageFileGetMetadataFromBuf):
(virStorageFileFreeMetadata): Manage it
(absolutePathFromBaseFile): Store absolute names in canonical form.
Requiring pre-allocation was an unusual idiom. It allowed iteration
over the backing chain to use fewer mallocs, but made one-shot
clients harder to read. Also, this makes it easier for a future
patch to move away from opening fds on every iteration over the chain.
* src/util/storage_file.h (virStorageFileGetMetadataFromFD): Alter
signature.
* src/util/storage_file.c (virStorageFileGetMetadataFromFD): Allocate
return value.
(virStorageFileGetMetadata): Update clients.
* src/conf/domain_conf.c (virDomainDiskDefForeachPath): Likewise.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo): Likewise.
* src/storage/storage_backend_fs.c (virStorageBackendProbeTarget):
Likewise.
Previously, no one was using virStorageFileGetMetadata, and for good
reason - it couldn't support root-squash NFS. Change the signature
and make it useful to future patches, including enhancing the metadata
to recursively track the entire chain.
* src/util/storage_file.h (_virStorageFileMetadata): Add field.
(virStorageFileGetMetadata): Alter signature.
* src/util/storage_file.c (virStorageFileGetMetadata): Rewrite.
(virStorageFileGetMetadataRecurse): New function.
(virStorageFileFreeMetadata): Handle recursion.
When an image has no backing file, using VIR_STORAGE_FILE_AUTO
for its type is a bit confusing. Additionally, a future patch
would like to reserve a default value for the case of no file
type specified in the XML, but different from the current use
of -1 to imply probing, since probing is not always safe.
Also, a couple of file types were missing compared to supported
code: libxl supports 'vhd', and qemu supports 'fat' for directories
passed through as a file system.
* src/util/storage_file.h (virStorageFileFormat): Add
VIR_STORAGE_FILE_NONE, VIR_STORAGE_FILE_FAT, VIR_STORAGE_FILE_VHD.
* src/util/storage_file.c (virStorageFileMatchesVersion): Match
documentation when version probing not supported.
(cowGetBackingStore, qcowXGetBackingStore, qcow1GetBackingStore)
(qcow2GetBackingStoreFormat, qedGetBackingStore)
(virStorageFileGetMetadataFromBuf)
(virStorageFileGetMetadataFromFD): Take NONE into account.
* src/conf/domain_conf.c (virDomainDiskDefForeachPath): Likewise.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo): Likewise.
* src/conf/storage_conf.c (virStorageVolumeFormatFromString): New
function.
(poolTypeInfo): Use it.
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.
* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/; If/. If/
Both LVM volumes and SCSI LUNs have a globally unique
identifier associated with them. It is useful to be able
to query this identifier to then perform disk locking,
rather than try to figure out a stable pathname.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Prevents libvirt from treating RBD backing stores as files. Without this
patch, creating a domain with a qcow2 overlay on an RBD would fail.
This patch essentially extends 9c7c4a4fc5,
which allows nbd backing stores, to allow rbd backing stores.
Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)
You should have received a copy of the GNU General Public License
along with Foobar. If not, see <http://www.gnu.org/licenses/>.
This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').
Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:
src/security/security_selinux.h
src/security/security_driver.h
src/security/security_selinux.c
src/security/security_apparmor.h
src/security/security_apparmor.c
src/security/security_driver.c
The code is splattered with a mix of
sizeof foo
sizeof (foo)
sizeof(foo)
Standardize on sizeof(foo) and add a syntax check rule to
enforce it
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Detected by Coverity. the only case is caller passes a NULL to 'format' variable,
then taking 'if (format)' false branch, the function qcow2GetBackingStoreFormat
will directly dereferences the NULL 'format' pointer variable.
Signed-off-by: Alex Jia <ajia@redhat.com>
Coverity complained that 395 out of 409 virAsprintf calls are
checked, and therefore assumed that the remaining cases are bugs
waiting to happen. But in each of these cases, a failed virAsprintf
will properly set the target string to NULL, and pass on that
failure to the caller, without wasting efforts to check the call.
Adding the ignore_value silences Coverity.
* src/conf/domain_audit.c (virDomainAuditGetRdev): Ignore
virAsprintf return value, when it behaves like we need.
* src/network/bridge_driver.c (networkDnsmasqLeaseFileNameDefault)
(networkRadvdConfigFileName, networkBridgeDummyNicName)
(networkRadvdPidfileBasename): Likewise.
* src/util/storage_file.c (absolutePathFromBaseFile): Likewise.
* src/openvz/openvz_driver.c (openvzGenerateContainerVethName):
Likewise.
* src/util/command.c (virCommandTranslateStatus): Likewise.
Getting metadata on storage allocates a memory (path) which need to
be freed after use otherwise it gets leaked. This means after use of
virStorageFileGetMetadataFromFD or virStorageFileGetMetadata one
must call virStorageFileFreeMetadata to free it. This function frees
structure internals and structure itself.
Detected by Coverity. The code was doing math on shifted unsigned
char (which promotes to int), then promoting that to unsigned long
during assignment to size. On 64-bit platforms, this risks sign
extending values of size > 2GiB. Bug present since commit
489fd3 (v0.6.0).
I'm not sure if a specially-crafted bogus qcow2 image could
exploit this, although it's probably not possible, since we
were already checking for the computed results being within
range of our fixed-size buffer.
* src/util/storage_file.c (qcowXGetBackingStore): Avoid sign
extension.
Spotted by coverity. Triggers on failed stat, although I'm not sure
how easy that condition is, so I'm not sure if this is a runtime
memory hog. Regression introduced in commit 8077d64 (unreleased).
* src/util/storage_file.c (virStorageFileGetMetadataFromFD):
Reduce need for malloc, avoiding a leak.
Since directories can be used for <filesystem> passthrough, they are
basically storage volumes.
v2:
Skip ., .., lost+found dirs
v3:
Use gnulib last_component
v4:
Use gnulib "dirname.h", not system <dirname.h>
Don't skip lost+found
This patch makes two corrections to the newly-added QED support patch series:
- Correct the QED header field offsets
- Remove XML parsing for VIR_STORAGE_FILE_AUTO_SAFE
Signed-off-by: Adam Litke <agl@us.ibm.com>
Implement getBackingStore() for QED images. The header format is defined in
the QED spec: http://wiki.qemu.org/Features/QED .
Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Stefan Hajnoczi <stefan.hajnoczi@uk.ibm.com>
Cc: Anthony Liguori <aliguori@linux.vnet.ibm.com>
Add an entry in fileTypeInfo for QED image files.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Stefan Hajnoczi <stefan.hajnoczi@uk.ibm.com>
Cc: Anthony Liguori <aliguori@linux.vnet.ibm.com>
Disk image formats that wish to opt-out of version validation are supposed to
set versionOffset to -1 in their fileTypeInfo entry.
By unconditionally returning False for these formats,
virStorageFileMatchesVersion() incorrectly reports a version mismatch when the
test was actually skipped. The correct behavior is to return True so these
formats can be successfully probed using the magic bytes alone.
Signed-off-by: Adam Litke <agl@us.ibm.com>
I am trying to use a qcow image with libvirt where the backing 'file' is a
qemu-nbd server. Unfortunately virDomainDiskDefForeachPath() assumes that
backingStore is always a real file so something like 'nbd:0:3333' is rejected
because a file with that name cannot be accessed. Note that I am not worried
about directly using nbd images. That would require a new disk type with XML
markup, etc. I only want it to be permitted as a backingStore
The following patch implements danpb's suggestion:
> I think I'm inclined to push the logic for skipping NBD one stage higher.
> I'd rather expect virStorageFileGetMetadata() to return all backing
> stores, even if not files. The virDomainDiskDefForeachPath() method
> should definitely ignore non-file backing stores though.
>
> So what I'm thinking is to extend the virStorageFileMetadata struct and
> just add a 'bool isFile' field to it. Default this field to true, unless
> you see the prefix of nbd: in which case set it to false. The
> virDomainDiskDefForeachPath() method can then skip over any backing
> store with isFile == false
Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
Using automated replacement with sed and editing I have now replaced all
occurrences of close() with VIR_(FORCE_)CLOSE() except for one, of
course. Some replacements were straight forward, others I needed to pay
attention. I hope I payed attention in all the right places... Please
have a look. This should have at least solved one more double-close
error.
NFS does not support file labelling, so ignore this error
for stdin_path when on NFS.
* src/security/security_selinux.c: Ignore failures on labelling
stdin_path on NFS
* src/util/storage_file.c, src/util/storage_file.h: Refine
virStorageFileIsSharedFS() to allow it to check for a
specific FS type.
Require the disk image to be passed into virStorageFileGetMetadata.
If this is set to VIR_STORAGE_FILE_AUTO, then the format will be
resolved using probing. This makes it easier to control when
probing will be used
* src/qemu/qemu_driver.c, src/qemu/qemu_security_dac.c,
src/security/security_selinux.c, src/security/virt-aa-helper.c:
Set VIR_STORAGE_FILE_AUTO when calling virStorageFileGetMetadata.
* src/storage/storage_backend_fs.c: Probe for disk format before
calling virStorageFileGetMetadata.
* src/util/storage_file.h, src/util/storage_file.c: Remove format
from virStorageFileMeta struct & require it to be passed into
method.
The virStorageFileGetMetadataFromFD did two jobs in one. First
it probed for storage type, then it extracted metadata for the
type. It is desirable to be able to separate these jobs, allowing
probing without querying metadata, and querying metadata without
probing.
To prepare for this, split out probing code into a new pair of
methods
virStorageFileProbeFormatFromFD
virStorageFileProbeFormat
* src/util/storage_file.c, src/util/storage_file.h,
src/libvirt_private.syms: Introduce virStorageFileProbeFormat
and virStorageFileProbeFormatFromFD
Instead of including a field in FileTypeInfo struct for the
disk format, rely on the array index matching the format.
Use verify() to assert the correct number of elements in the
array.
* src/util/storage_file.c: remove type field from FileTypeInfo
When QEMU opens a backing store for a QCow2 file, it will
normally auto-probe for the format of the backing store,
rather than assuming it has the same format as the referencing
file. There is a QCow2 extension that allows an explicit format
for the backing store to be embedded in the referencing file.
This closes the auto-probing security hole in QEMU.
This backing store format can be useful for libvirt users
of virStorageFileGetMetadata, so extract this data and report
it.
QEMU does not require disk image backing store files to be in
the same format the file linkee. It will auto-probe the disk
format for the backing store when opening it. If the backing
store was intended to be a raw file this could be a security
hole, because a guest may have written data into its disk that
then makes the backing store look like a qcow2 file. If it can
trick QEMU into thinking the raw file is a qcow2 file, it can
access arbitrary files on the host by adding further backing
store links.
To address this, callers of virStorageFileGetMeta need to be
told of the backing store format. If no format is declared,
they can make a decision whether to allow format probing or
not.
virStorageFileIsSharedFS would previously only work if the entire path
in question was stat'able by the uid of the libvirtd process. This
patch changes it to crawl backwards up the path retrying the statfs
call until it gets to a partial path that *can* be stat'ed.
This is necessary to use the function to learn the fstype for files
stored as a different user (and readable only by that user) on a
root-squashed remote filesystem.
A look at the QEMU source revealed the missing bits of info about
the VPC file format, so we can enable this now
* src/util/storage_file.c: Enable VPC format, providing version
and disk size offset fields
Do not require each caller of virStorageFileGetMetadata and
virStorageFileGetMetadataFromFD to first clear the storage of the
"meta" buffer. Instead, initialize that storage in
virStorageFileGetMetadataFromFD.
* src/util/storage_file.c (virStorageFileGetMetadataFromFD): Clear
"meta" here, not before each of the following callers.
* src/qemu/qemu_driver.c (qemuSetupDiskCgroup): Don't clear "meta" here.
(qemuTeardownDiskCgroup): Likewise.
* src/qemu/qemu_security_dac.c (qemuSecurityDACSetSecurityImageLabel):
Likewise.
* src/security/security_selinux.c (SELinuxSetSecurityImageLabel):
Likewise.
* src/security/virt-aa-helper.c (get_files): Likewise.
* configure.ac: Check for <linux/magic.h>.
* src/util/storage_file.c: Include <linux/magic.h> only if present.
Linux kernels prior to 2.6.19 lacked it.
[__linux__] (NFS_SUPER_MAGIC): Define if not already defined.
When QEMU runs with its disk on NFS, and as a non-root user, the
disk is chownd to that non-root user. When migration completes
the last step is shutting down the QEMU on the source host. THis
normally resets user/group/security label. This is bad when the
VM was just migrated because the file is still in use on the dest
host. It is thus neccessary to skip the reset step for any files
found to be on a shared filesystem
* src/libvirt_private.syms: Export virStorageFileIsSharedFS
* src/util/storage_file.c, src/util/storage_file.h: Add a new
method virStorageFileIsSharedFS() to determine if a file is
on a shared filesystem (NFS, GFS, OCFS2, etc)
* src/qemu/qemu_driver.c: Tell security driver not to reset
disk labels on migration completion
* src/qemu/qemu_security_dac.c, src/qemu/qemu_security_stacked.c,
src/security/security_selinux.c, src/security/security_driver.h,
src/security/security_apparmor.c: Add ability to skip disk
restore step for files on shared filesystems.
* src/util/util.h (virAsprintf): Remove ATTRIBUTE_RETURN_CHECK, since
it is perfectly fine to ignore the return value, now that the pointer
is guaranteed to be set to NULL upon failure.
* src/util/storage_file.c (absolutePathFromBaseFile): Remove now-
unnecessary use of ignore_value.
* src/util/storage_file.c (absolutePathFromBaseFile): While this use
of virAsprintf is slightly cleaner than using stpncpy(stpcpy(...,
it does impose an artificial limitation on the length of the base_file
name. Rather than asserting that it does not exceed INT_MAX, return
NULL when it does.
